For the lack of economic rent restricted in the scope product cost， this paper is presented the conception of generalized economic rent， including transaction cost and opportunity benefit. The mechanism of Ricardian Rents， Schumpterican Rents， Chamberlain Rents and Relationship Rents generated by IT investment is analyzed. The further research focuses on the judgment criteria and the formation conditions of continuous rents， and explains the reason why IT doesn't matter.